One vertex per element, one color per generator, with an edge from x to x·s.
(1,2,5,3)(4,7,8,6)(9,10,15,16)(11,12,13,14)(19,23)(22,24)(25,26)(27,31)(28,32)(29,30)(33,35)(34,39)(36,40)(37,38)(1,2,5,3)(4,7,8,6)(9,11,15,13)(10,12,16,14)(18,21)(22,24)(26,30)(31,33)(32,38)(39,40)(2,3)(6,7)(9,12,15,14)(10,11,16,13)(17,18)(19,22)(20,21)(23,24)(25,26)(27,33)(28,32)(29,30)(31,35)(34,40)(36,39)(37,38)(1,3,5,2)(4,7,8,6)(9,13,15,11)(10,12,16,14)(25,27,29,35)(26,31,30,33)(28,36,37,34)(32,40,38,39)(1,4,5,8)(2,6,3,7)(9,14,15,12)(10,11,16,13)(17,19)(18,22)(20,23)(21,24)(25,28,29,37)(26,32,30,38)(27,34,35,36)(31,39,33,40)A Cayley diagram is a choice, not a fact about the group. Another drawing of this group — in a book, or on a different generating set — may look nothing like this one.